On Linux-based operating system the /etc directory is used to hold global configuration files for applications and services. A good set of configurations is really important for a good working system, so being able to keep track of changes and quickly revert them, in case something go wrong, is crucial. Etckeeper helps us achieve this goal keeping configuration files under version control.
When we need to schedule a task on a Linux system we can use utilities like cron or systemd-timers. Various implementations of cron exist, but they have in common the fact that they run as a system service, and are designed to be used on systems which are always up and running, like servers. When we need to schedule a task on a desktop or a notebook, which are turned off more often, we can use anacron instead.